

A079407


Numbers n such that the least s>=0 such that sum(k=0,n,(k+s)!/C(n,k)) is an integer satisfies s=n1.


0



1, 2, 4, 5, 13, 17, 19, 23, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


LINKS

Table of n, a(n) for n=1..33.


FORMULA

Seems that sequence consists of 1, 2, 4, 5, 13, 17, 19, 23 union primes >=31


PROG

(PARI) for(n=1, 150, s=0; while(frac(sum(k=0, n, (k+s)!/binomial(n, k)))>0, s++); if(ns==1, print1(n, ", ")))


CROSSREFS

Sequence in context: A102932 A128457 A139485 * A078652 A289491 A102992
Adjacent sequences: A079404 A079405 A079406 * A079408 A079409 A079410


KEYWORD

nonn


AUTHOR

Benoit Cloitre, Feb 16 2003


STATUS

approved



